Drivers ICs or drivers LSI for a liquid crystal display are mounted in a structure of TCP (Tape Carrier Package) or COF (Chip on Film). Such a structure is referred to as a TAB (Tape Automated Bonding) tape. A film mounting IC or LSI is used as a semiconductor chip mounted on the TAP tape.
According to such a TAB tape, a circuit is provided on a tape-like film on which the semiconductor chips are mounted and wiring patterns are provided. The TAB tape is therefore entirely thin and can be bent freely to some extent in any place. Therefore, the TAB tape is contributory in making the liquid crystal display smaller and thinner. Against a backdrop of this, in order to win a recent price competition for a television set in which the liquid crystal display is mounted, the TAB tape is required to be produced at higher productivity. In order to achieve such higher productivity, for example, the TAB tape is required to be longer.
Conventionally, in view of workability and easiness of storage and transportation, the TAB tape which has been subjected to the mounting of the semiconductor chips is packaged while being wound on a reel and is then shipped and transported. In this case, the TAB tape has been wound concurrently with a tape on which protruding parts serving as cushioning are provided (this tape is referred to as a so-called spacer tape or an embossed tape). This is intended to (i) protect a surface of the TAB tape wound on the reel on which surface the circuit is provided and (ii) mechanically protect the semiconductor chips from an external force.
FIG. 23 is a cross-sectional view illustrating a state where a TAB tape 550 has been wound on a reel by use of a conventional spacer tape 500.
According to the conventional spacer tape 500 embossed parts 502 are provided on one surface of a tape 501 and embossed parts 503 are provided on the other surface of the tape 501. The embossed parts 502 and the embossed parts 503 are alternately provided at regular intervals at opposite ends of the tape 501. The embossed parts 502 and the embossed parts 503 have a substantially identical height, which has been sufficiently secured so that a surface of the TAB tape 550 on which surface a circuit is provided is protected.
However, a length of the TAB tape 550 for which length the TAB tape 550 can be wound on one (1) reel depends on a total thickness of the spacer tape 500 which total thickness includes the heights of the embossed parts 502 and the embossed parts 503. As the spacer tape 500 has a larger total thickness, a winding outline becomes larger even in a case where the TAB tape 550 which has an identical length is wound on the reel. In view of this, it is necessary to replace the reel with a larger reel.
However, a reel for shipping and transportation has a substantially standardized size. A small-sized reel has a size of Φ 405 mm and a next-larger reel has a size of Φ 530 mm. In view of this, an increase in size of the reel from Φ 405 mm to Φ 530 mm or merely a longer TAB tape causes the reel to be larger. This causes an increase in capital investment in replacing the small-sized reel with the next-larger reel which is expensive and improving in structural strength. Further, a larger reel causes problems of (i) an increase in necessary storage space, (ii) a decrease in productivity per floor area, and (iii) an increase in transportation cost. Hence, the larger reel causes no improvement in productivity due to these problems. It is therefore difficult in the conventional spacer tape 500 to cause the TAB tape 550 to be longer.
In contrast, Patent Literatures 1 and 2 disclose spacer tapes in each of which a TAB tape is larger.
FIG. 24 is a cross-sectional view illustrating a state where a TAB tape 550 has been wound on a reel by use of a spacer tape 600 disclosed in Patent Literature 1.
According to the spacer tape 600, protruding parts 602 are provided on one surface of a tape 601 and protruding parts 603 are provided on the other surface of the tape 601. The protruding parts 602 and the protruding parts 603 are alternately provided at regular intervals at opposite ends of the tape 601. The protruding parts 603 have a lower height than the protruding parts 602. This prevents damage to both the first and second surfaces of the TAB tape 550 and causes an increase in amount of winding of the TAB tape 550.
FIG. 25 is a cross-sectional view illustrating a state where a TAB tape 750 has been wound on a reel by use of a spacer tape 700 disclosed in Patent Literature 2.
The spacer tape 700 has protruding parts 702 provided only on a single surface of a tape 701. The protruding parts 702 are provided at regular intervals at opposite ends of the tape 701. The spacer tape 700 is effectively used in a case where it is only necessary to protect only a single surface of the TAB tape 750 on which semiconductor chips have not yet been mounted. According to the spacer tape 700, the protruding parts 702 are provided only on its single surface. This causes an increase in amount of winding of the TAB tape 750.
Patent Literature 1
Japanese Patent Application Publication, Tokukai, No. 2004-327550 A (Publication Date: Nov. 18, 2004)
Patent Literature 2
Japanese Patent Application Publication, Tokukaihei, No. 6-80177 A (Publication Date: Mar. 22, 1994)
Patent Literature 3
Japanese Patent Application Publication, Tokukai, No. 2006-310476 A (Publication Date: Nov. 9, 2006)